Breastplate of Kamvuul Norek

This adamantine Breastplate of ancient Dhaakan belonged to a hobgoblin hero known as a mighty slayer of Aberrations.
While wearing this armor, you gain a +2 bonus to Armor Class, any Critical Hit against you becomes a normal hit, and you have Advantage on saving throws against spells and other magical effects.
Additionally, if you succeed on a saving throw against the Mind Blast ability of a Mind Flayer or other Aberration, you are unaffected, and the effect is reflected back toward the Aberration as if the cone originated from you, including the Aberration in its area of effect.